title: Simple and generalized synthesis of oxide-metal heterostructured nanoparticles and their applications in multimodal biomedical probes.
abstract: Heterostructured nanoparticles composed of metals and Fe3O4 or MnO were synthesized by thermal decomposition of mixtures of metal-oleate complexes (for the oxide component) and metal-oleylamine complexes (for the metal component). The products included flowerlike-shaped nanoparticles of Pt-Fe3O4 and Ni-Fe3O4 and snowmanlike-shaped nanoparticles of Ag-MnO and Au-MnO. Powder X-ray diffraction patterns showed that these nanoparticles were composed of face-centered cubic (fcc)-structured Fe3O4 or MnO and fcc-structured metals. The relaxivity values of the Au-MnO and Au-Fe3O4 nanoparticles were similar to those of the MnO and Fe3O4 nanoparticles, respectively. Au-Fe3O4 heterostructured nanoparticles conjugated with two kinds of 12-base oligonucleotide sequences were able to sense a complementary 24-mer sequence, causing nanoparticle aggregation. This hybridization-mediated aggregation was detected by the overall size increase indicated by dynamic light scattering data, the red shift of the surface plasmon band of the Au component, and the enhancement of the signal intensity of the Fe3O4 component in T2-weighted magnetic resonance imaging.
authors.affiliation: National Creative Research Initiative Center for Oxide Nanocrystalline Materials and School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Korea.
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Choi
authors.forename: Hyon Bin
authors.initials: HB
authors.lastname: Na
authors.forename: Yong Il
authors.initials: YI
authors.lastname: Park
authors.forename: Kwangjin
authors.initials: K
authors.lastname: An
authors.forename: Soon Gu
authors.initials: SG
authors.lastname: Kwon
authors.forename: Youngjin
authors.initials: Y
authors.lastname: Jang
authors.forename: Mi-Hyun
authors.initials: MH
authors.lastname: Park
authors.forename: Jaewon
authors.initials: J
authors.lastname: Moon
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Son
authors.forename: In Chan
authors.initials: IC
authors.lastname: Song
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
authors.forename: Taeghwan
authors.initials: T
authors.lastname: Hyeon
mesh_terms: D003460:Crystallization; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D015335:Molecular Probes / Q000737:chemistry*; D010087:Oxides / Q000138:chemical synthesis* / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D015335:Molecular Probes; D010087:Oxides